Presentation
Diminished left ear hearing, left facial numbness and headache.
Patient Data
Decreased girth of the left trigeminal nerve with prominent central longitudinal high T2 signal along its cisternal segment, suggestive of chronic atrophic changes of the left trigeminal nerve. No abnormal enhancement noted.
The left superior cerebellar artery is coursing just above the left trigeminal nerve abutting its superior surface, suggestive of neurovascular compression.
Annotated T2WI images demonstrating the relationship of the left superior cerebellar artery (SCA) to the left trigeminal nerve.
Decreased girth of the left trigeminal nerve measuring 2.1 mm in thickness compared to 3.0 mm of the right one. It shows prominent central longitudinal high T2 signal along its cisternal segment.
Case Discussion
This case demonstrates chronic atrophic changes of the left trigeminal nerve in a patient with trigeminal neuralgia due to compression of the trigeminal nerve by the superior cerebellar artery. The artery is seen abutting the superior surface of the left trigeminal nerve. The presence of decreased nerve thickening (discrepancy in girth) and signal alteration are suggestive of chronic atrophic changes due to neurovascular compression syndrome.
The associated complaint of diminished hearing of the left ear may be attributed to the innervation of the tensor tympani muscle by the affected trigeminal nerve, the only ear muscle supplied by it through the nerve to medial pterygoid.